Thermal responsive device



July 1, 1958 c. W. BoNDURAN-r 2,841,014

THERMAL RESPONSIVE DEVICE lFiled Sept. 7, 1954 lNVENoR.

CARLTON W. BONDURANT HIS ATTORNEYS nit-ed States Patent O THERMAL RESPNSIVE DEVICE Carlton W. Bondurant, Dayton, Ohio, assignor to Stand ardThomson Corporation, Vandalia, Ohio, a corporation of Delaware Application September 7, 1954, Serial No. 454,591

4 Claims. (Cl. 742) This invention relates to a thermal responsive device. The invention relates more particularly to a device which is automatically actuated upon subjection to a predetermined abnormal, temperature. The invention relates still more` particularly to a thermal responsive device which is adapted to actuate signal means or control means. However, the invention is not so limited in that it may be used in other types of applications and for other purposes.

An object of this invention is to provide a thermal responsive device which is automatically actuated at a certain predetermined abnormally high temperature and which device may be easily reset when the temperature to which it is subjected has been reduced in value below the operating point thereof.

Another object of this invention is to provide a thermal responsive device in which the operating members thereof are easily and readily removable or interchangeable.

Another object of this invention is to provide a thermal responsive device which has a very sensitive temperature indicating means.

Another object of this invention is to provide a thermal responsive device in which the operating elements thereof are covered and, hence, are protected from damage by engagement therewith.

Another object of this invention is to provide a thermal 'responsivedevice which, when in actuated position, gives visible indication thereof.

Other objects and advantages reside in the construction of parts, the combination thereof and the mode of operation, as will become more apparent from the following description.

ln the drawing,

Figure l is a side sectional view showing the thermal responsive device of this invention in its fle-actuated position.

Figure 2 is a side elevational view similar to that of Figure l showing the device of this invention in an actuated position.

Figure 3 is a sectional view taken substantially on line 3-3 of Figure l.

Figure 4 is a fragmentary sectional view showing the manner in which the operating members of the device may be easily removed from the body of the device.

Figure 5 is a sectional view taken Isubstantially on line 5 5 of Figure 1.

Referring to Vthe drawing in detail, a thermal responsive device of this invention comprises a body member 1i) provided with an internal cavity 12. The body is also provided with a cylindrical bore 14 which extends from the cavity 12 to the end of the body 10. The bore 14 thus provides an opening at one end of the body 10 leading to the cavity 12.

Within the bore 14 is threadedly mounted a guide bearing 16 provided with an elongate hole therethrough within which .an actuator rod 18 is slidably mounted.

The rod 18 extends from the cavity 12 through the guide bearing 16 and from the body 10.

At the end of the body member 10 is a cradle member 20 which is freely and rotatably attached thereto by means of a ring member 22. Between the ring membei 22 and the upper portion of the body 10 is provideda groove within which an inwardly extending annular base 26 0f the cradle 20 is freely movable.

The cradle member 20 also comprises a flange member 28 which terminates in an arcuately downwardly extending hook member or abutment member 3l). Opposite the ilange 28, the cradle 20 is provided with a vertical wall member 32 which has an elongate vertical groove 34 therein.

Rigidly attached at the upper end of the rod 18, which extends from the body 1t), is a plate member 38 which is normal to the axis of the rod 18. The plate member 8 has an end portion 4t) which extends into the groove 34 of the vertical wall 32. Slidable engagement of the plate 38 within the groove 34 prevents rotation of the cradle 2.8 with respect to the rod member 18. The other end of the plate 38 is provided with a short upwardly extending hook member 44.

Attached to the plate 38 is a bearing bracket 48 which supports a bearing housing 50. Rotatably carried by the bearing housing Sil and the bearing bracket 48 is a shaft member 54. Firmly attached to the shaft S4 is a wheel 56 provided with teeth 60. Each of the teeth oil has a radial surface 62.

Within the bearing housing 50 is a body of fusible material 64, such as solder or any other suitable substance. The fusible material 64 nearly surrounds the shaft member 54 as it engages the shaft member 54 at the end thereof and along most of the length thereof, as clearly shown in Figure 5. The fusible material 64 in a solid state thus firmly secures the shaft 54 to the bearing housing 58 so that the shaft 54 is unable to rotate within the bearing housing Sil. The hook member 30 is adapted to engage a radial surface 62 of one of the teeth 60 of the wheel 56, as shown in Figure l. When the solid condition of the fusible material 64 retains the shaft 54 from rotation, the wheel 56 is, of course, unable to rotate. Hence, the wheel 56 with its bearing housing Sil and fusible material 64 acts as a thermal responsive latch mechanism cooperable with the hook member Sil. Thus, when the hook 3i) engages a radial surface 62 of one of the teeth 60 of the wheel 56, as shown in Figure 1, movement of the rod 18 from the body it) is prevented.

Within the cavity l2 of the body l0 is a compression spring 68 which engages an abutment plate 70. The rod member 18 is provided with a comparatively small diameter portion 72 so that a shoulder 74 is formed between the larger diameter of the rod 18 and the smaller diameter 72 thereof. The smaller diameter portion 72 is encircled by the compression spring 68. The abutment plate 70 is forced against the shoulder 74 of the rod 18 by the compression spring 68. Thus, the compression spring 68 urges the rod 18 in a direction from the cavity 12 of the body 10. However, as stated above, the hook member 3) which engages the wheel 56 prevents movement of the rod 18 from the body 10, as shown in Figure 1, when the fusible material 64 is solidified.

At the upper portion of the bearing housing 50 is a block member 76 to which is attached a connector plate 77 of a cup-shaped hood member 78. The bearing housing Si) also is attached to the hood 78 by means of an extension 8i) of the bearing housing 50. The cup-shaped hood member '78 in its inverted position acts as a protective covering over the moving elements of the thermal responsive device. However, the hood 78,

rotate. vattached to the shaft`54, the wheel 56 may rotate when 56 is unable to rotate.

-which is made of any suitable thermal conductive, -materiaL also acts as a thermal conductor for the fusible aboye the fusing pointof the fusible material, the hood 78, acting as a conductor, readily transfers heat into the bearing housing 50, melting the fusible material `therein and releasing the shaft 54 so that it is freeto Due to the fact that the wheel 56 is firmly the fusible material 64 is in its fused state.

The rodmernber 18, urged by the spring 68, thus causes rotation of the Wheel 56 as the bearing housing .50 is forced upwardly, rotatively disengaging the Wheel 56 from the hook 30. Thus, the rod member 18 forced by the spring 68 is permitted to move in a direction from the body 10.

The movement of the rod 1S by means of the spring 68 is limited by engagement of the abutment plate 70 with an end wall 82 of the cavity 12, as shown in Figure 2.

The rod 18 may be attached to any suitable indicating means or control means so that upon axial movement of the rod 18 from the position as shown in Figure 1 to the position as shown in Figure 2, the indicating or control means is actuated. Of course, such actuation indicates that a certain predetermined temperature has been reached at the location of the thermal responsive device.

When the temperature at the location of the thermal responsive device decreases sufficiently that the fusible material 64 re-solidies, the shaft 54 is again firmly attached to the bearing housing 50 so that the shaft 54 is once more unable to rotate. Hence, the wheel member By manually pressing upon the hood 78, moving the bearing housing 50 and the wheel 56 toward the body 10, the wheel 56 is again placed in latched engagement with the hook 30, as one of the teeth 60 of the wheel 56 is engaged by the hook 30. Due to the fact that the groove 34 within the vertical wall 32 prevents rotation of the plate 38 with respect to the cradle 20, the hook member 30 always is in proper alignment to engage the wheel 56. Furthermore, due to the fact that the cradle 26 is rotatably mounted upon the body 10, the cradle, with the other elements including the hood 78, may rotate as a unit. Due to the fact that the hood 78 may be obviously accessible to an observer of the device, such observer may intentionally or unintentionally manually grasp the hood 78 and attempt to rotate the hood. If such rotation is attempted, the entire unit rotates with respect to the body and no damage results.

In order to prevent the rod member 18 from being withdrawn entirely from within the body 10, the upwardly extending hook member 44 of the plate 38 is adapted to contact the hook 30 of the ilange 23, as best shown in Figure 4, so that the rod member 18 and the elements attached thereto may not be withdrawn from the body 10. Howevenif it is desired to make such a removal, all-that is necessary is to cause the flange member 28 to be bent outwardly as shown by the dotted lines in Figure 4, so that upon outward movement of the rod 18 from the body 10, the hook 30 is not engaged by the hook 44. If the tiange 28 is so bent outwardly, the bearing housing 50 with the hood 78 including the rod 18 may be removed from the body 10. Hence, removal and repair or replacement of these members is readily and easily possible.

Thus, it may be understood that the thermal responsive device of this invention provides means by which a high temperature may be indicated and/or controlled. After the device has been actuated, as shown in Figure 2, to respond to indication of an abnormal temperature, the device may be easily reset to the position shown in Figure v1 after the temperature has decreased below the operating value of the thermal responsive device. Naturally, it is to be understood that the operating value or the operating temperature of the device is .the fusing point of the fusible material 64 within the bearing housing 50. Hence, a fusible material for a particular application is chosen in accordance with the fusing point of the material and the desired operating temperature of the device.

Within the body 10 may be located any suitable control or indicating apparatus for actuation by the rod 18 upon axial movement thereof.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and dened in the appended claims.

Having' thus described my invention, I claim:

p 1. In a thermal responsive device comprising a tubular -enclosing body, a rod longitudinally movable within said body and extending therefrom, a spring urging movement of said. rod from said body, a cradle rotatably attached to the end of said body and encircling the rod, the cradle including a guide wall and a hook member, the guide Wall being provided with an elongate slot, a plate attached at the end of said rod normal to the axis thereof, the plate Yhaving an end extending into the elongate slot of the guide wall, the other end of the plate having an arcuate portion, a bearing blockattached to the plate, a rotatable vshaft journalled in said bearing block normal to said rod,

Vpredetermined high temperature the fusible material melts permitting rotation of said shaft, thus permitting rotational release of said wheel from the hook member releasing the rod for axial movement in a direction from said body, movement of the rod from said body being limited by engagement of the arcuate portion of said plate with the hook member of the cradle.

2. A thermal device including a support body, an

actuator rod movably supported within said body and having an end portion extending therefrom, a resilient spring urging said actuator rod from said support body, an abutment flange rotatably attached to said support body atthe exterior thereof, a latch member attached to said vrod and engageable with said abutment flange to retain the actuator rod from movement from the support body,

`and thermal responsive means attached to said latch member releasing said latch member for operation upon subjection to a predetermined temperature, release of said latch member permitting movement ofsaid actuator rod by said spring in a direction from said support body.

3. A thermal device comprising a support body, the support body having a cavity therein Iprovided with an opening at one end thereof, an elongate actuator member Within the cavity of the support body and having an end portion extending therefrom through the opening thereof, means urging the actuator member in a direction from the support body, a shaft rotatably attached to the end portion of the actuator member, a notched wheel attached to the shaft, fusible material attached to the shaft and to the end portion of the actuator member for retaining the shaft from rotation until the fusible material is subjected toa given predetermined temperature, an arcuate hook member rotatably attached to the exterior of the support body adjacent the open end of the cavity and engageable with the notched wheel for retaining the actuator member from movement in a direction from the support body, means attached to the actuator member and to support body maintaining alignment of the hook member with the notched wheel, the fusible material releasing the shaft for rotation upon subjection of the fusible material to the given predetermined temperature thus permitting rotation of the shaft and movement of the notched Wheel, thus resulting in movement of the actuator member.

4. A thermal responsive device for indicating a predetermined abnormal temperature within a room comprising a support body, the support body having a cavity therein provided with an opening at one end thereof, an elongate actuator member within the cavity of the support body and having an end portion extending therefrom through the opening thereof, resilient means urging the actuator member in a direction from the support body, a guide member rotatably attached to the exterior of the support body and encompassing the open end of the cavity, the guide member extending from the support body in a. direction parallel to the actuator member, a bearing block attached to the end portion of the actuator member exterior of the housing, a shaft rotatably supported by the bearing block, a notched Wheel attached to the shaft, fusible material attached to the shaft and to the bearing block for retaining the shaft from rotation until the fusible material is subjected to a given predetermined temperature, an arcuate hook attached to the guide member and engageable with the notched Wheel for retaining the actuator member from movement in a direction from the support body, a projection extending from the bearing block and slidably engageable with the guide member, a hood member attached to the bearing block and adapted to be disposed Within a room, the hood member encompassing the bearing block, the hood member transferring room heat to the fusible material releasing the shaft for rotation upon subjection of the fusible material to the given predetermined temperature, thus permitting movement of the notched Wheel, thus permitting movement of the actuator member in a direction from the support body, and an abutment member extending from the bearing block and engageable by the arcuate hook member upon sufficient movement of the actuator member in a direction from the support body.

References Cited in the le of this patent UNITED STATES PATENTS Brown Apr. 20, 1954 

